Electric heating unit

ABSTRACT

An electric heating unit includes an inner casing containing a plurality of heating rods. An outer casing comprising interlocked front and back panels surrounds the inner casing in spaced relation thereto to define front and rear air channels between the panels and the casing the panels are so shaped as to cause the air channels to merge at the top and bottom of the unit and communicate with an upper air outlet opening and a lower air inlet opening. At least one of the openings is of approximately the width of one of the air channels. Mechanical interlocking means at the ends of the panels hold them in the required spaced disposition relative to the inner casing. The heating rods are entirely enclosed within the inner casing whereby dust or other particles cannot come in contact therewith.

finite States Patent [191 Temrin 11] 3,829,656 [4 Aug. 13, 1974 1 ELECTRIC HEATING UNIT [22] Filed: Apr. 17, 1972 [21] Appl. No.: 244,506

Related US. Application Data [63] Continuation-in-part of Ser. No. 36,963, May 13,

1970, abandoned.

[52] US. Cl 219/367, 165/129, 219/342,

219/376, 239/79 [51] int. Cl H051) 1/00, F24d 13/00 [58] Field of Search 219/359, 365-370,

a & kc:

341,582 11/1959 Switzerland: 219/342 117,929 10/1969 Norway 219/366 24,739 6/1922 France 219/376 775,757 10/1934 France 219/530 Primary ExaminerA. Bartis 5 7] ABSTRACT An electric heating unit includes an inner casing containing a plurality of heating rods. An outer casing comprising interlocked front and back panels surrounds the inner casing in spaced relation thereto to define front and rear air channels between the panels and the casing the panels are so shaped as to cause the air channels to merge at the top and bottom of the unit and communicate with an upper air outlet opening and a lower air inlet opening. At least one of the openings is of approximately the width of one of the air channels. Mechanical interlocking means at the ends of the panels hold them in the required spaced disposition relative to the inner casing. The heating rods are entirely enclosed within the inner casing whereby dust or other particles cannot come in contact therewith.

3 Claims, 9 Drawing Figures PATENTEU AUG] 312m sum 1 BF 2 I I I a I I I I l 4 I I a l 4 I I A I l 4 I 4 I I I I 4 I fl I l4 mwwFw This application is a continuation-in-part of copending application Ser. No. 36,963 filed May 13,

1970, now abandoned.

BACKGROUND OF THE INVENTION Electric heaters or radiators as presently known are usually provided with a heat-emitting outer surface or surfaces the temperature of which may rise to above 100C when the electric circuit to them is closed. The highest permissible temperature, as far as a fire hazard is concerned, would be about 150C and therefore safety measures must be taken to prevent a higher temperature from being reached. Such higher temperature might easily happen if a cover of any sort was placed over the radiator, intentionally or otherwise, or if the radiator became loose and assumed a position in which it might lie on or in contact with the floor. A protective measure might be for example, the provision of a ledge. or similar element located above the radiator, to thereby prevent any object from being put directly on or over the radiator. Also suitable switches might be provided in the electric circuit.

In spite of these measures the temperature of the heat-emitting surfaces is sometimes sufficiently high to cause burns if, for example, a hand contacts with or is held against a radiator, the electric current to which is on. By reason of the high temperature a substantial portion of the heat emitted by the radiator is radiation heat, and this may in some cases, be inconvenient, as it is then required that the radiator be surrounded by a free space, if a uniform and desirable heat distribu-v tion in the room shall be obtained.

DESCRIPTION OF THE INVENTION The present invention relates to electric heating units or radiators such as those which are employed in heating buildings or rooms of various kinds. By means of the present invention, the drawbacks enumerated above are eliminated and the invention is characterized by the fact that baffle plates or panels are provided in spaced relation to one or more heat-emitting surfaces in such a manner that an air-flow passage or flue is provided between said plates or panels, which passage is open at the top and also at the bottom.

Through the passage thus formed, a convection air stream will be produced in operation, and which will convey a substantial portion of the heat away from the radiator, and the temperature at the surfaces of the plates which face away from the radiator and which will compose the visible surfaces, will become considerably lower than the temperature at the heat-emitting surface of the radiator. By this arrangement, a two-fold advantage is gained. By the increased convection, the radiator will heat a larger volume of air than a conventional radiator, in which a greater portion of the heat emitted is radiation heat which is often less readily distributed over the space to be heated. Furthermore, the novel arrangement affords a protection against burns since the temperature at the outer faces of the plates or panels is materially reduced to a harmless level for example, 35C and 40C.

The described arrangement contemplates the provision of an inner casing disposed within an outer casing or housing, the casings being in spaced relation in order to provide an air passage or flue between them, such flue being open at the top and bottom. The heating elements consisting of rods, coils or the like, are completely enclosed within the inner casing so that dust and other particles will not contact with these elements. Since the heating elements are not in physical contact with the outer casing or housing, the air passing through the air passage or flue will not contact with the heating elements but will be heated principally by convection by passing around the surfaces of the inner casing that is heated by radiation from the enclosed heating elements.

The baffle plates or panels may be composed of any I suitable material, such as those of heat resistant nature,

preferably sheet metal.

Referring to the accompanying drawings, wherein an illustrative embodiment of the invention is disclosed,

FIG. 1 is a vertical cross sectional view of an arrangement constructed in accordance with the invention;

FIG. 2 is a horizontal cross sectional view of the same, the section being taken along line 2-2 at right angles to that of FIG. 1;

FIG. 3 is a sectional view of a detail of FIG. 2, in an enlarged scale and showing the interfit of parts of the housing;

FIG. 4 is a cross sectional view along the line 4-4 of FIG. 3, looking in the direction of the arrows;

FIG. 5 is a side elevational view of an installed heating unit provided with baffle plates or panels disposed over its opposite faces;

FIG. 6 is a cross sectional view through the structure of FIG. 5;

FIG. 7 is a sectional view in perspective of parts of the heating unit;

FIG. 8 is a horizontal section taken through lines 99 of FIG. 9, and

FIG. 9 is a section taken along the lines 8-8 of FIG. 8 showing an arrangement constructed in accordance with the invention but with a slightly modified casing structure.

In FIG. 1 is shown a surface radiation unit including a casing 1, herein referred to as the inner casing, and which completely encloses the heating elements 2 such as rods, coils or the like, the same being suitably connected to a source of electric current to thereby provide the required heat.

The inner casing 1 may be made in the required size and shape and in the form clearly shown in FIGS. 1 and 7, it may consist of the plates 3 and 4 overlapped at their opposite end portions as shown at 5 and 6 in FIG. 7, such portions being secured together in their overlapped relation by screws 7. The heating elements or rods 2 are spaced from the walls of the inner casing, such walls being heated by radiation from the heat emitted from the rods.

The inner casing 1 is enclosed within an outer casing or housing, primarily composed of a pair of plates or panels 9 and 10, the panel 9 being spaced in such a manner from the inner casing 1 that an air flow passage 11 is provided between the panel 9 and the heated surface of the inner casing 1. This passage 11 is open both at the top 20 and at the bottom 21 as indicated by the arrows in FIG. 1. To better guide the air-flow, the plate 9 is, at its upper end shaped in such a way that the aperture 20 is of about the same width as that of the passage 11, the plate 9 being bent into a box section 15 extending over the whole width of the plate. At the bottom aperture 21, the plate may be shaped in the same way or it may be provided with a bent-back rim or flange 13 as illustrated.

The second plate or panel shown at 10 is provided at the opposite side of the housing 8, defining between itself and the inner casing a second air-flow passage 16 that merges with the air-flow passage 11 at the top and bottom of the assembly.

The embodiment of the invention is provided with panels or plates which may be attached to an existing radiator of the conventional type, but it is possible to provide the plate or plates while the radiator is being manufactured and the radiator can be permanently provided with the plates or panels at the opposite sides as indicated in the drawings.

The baffle plate or panel 9 of the housing and shown in FIGS. 2 and 3 of the drawings, is provided at its vertical or side edges 18 with inwardly directed flanges 19 having apertures or slits 24 for the reception of hookshaped securing member 30 at the ends of radiator casing 1. By the shape of these hook members the flanges 19 will closely engage a rim portion of the radiator, the latter being consequently enclosed by the plate with its rim portions. For the guiding of the bottom portion of the plate at 13 or 10 and to maintain the proper distance between the plates, tabs 27 can be provided on the plate to engage in apertures in the bottom portion of the radiator. The fastening or distance members may be shaped in numerous ways according to the shape of the plates of the outer casing or the radiators with which they are used. The fastening members may, for example, be formed as tabs resembling those indicated at 27 for engaging the top portion of the radiator and may be secured thereto with a snap action. Also, the distance members may be formed as tabs or tongues which abut against the radiator or they might be different types of washers or the like or other kinds of spacing members, the optimum being the securement of a suitable mounting for the plate or plates in the proper spaced relation to the inner casing containing the heater elements.

In the arrangement disclosed in FIG. 1, it will be noted that the upper and lower ends of the inner casing are located inwardly of the upper and lower ends of the housing and this arrangement permits the merging of the air-flow from the passages 11 and 16.

The parts of the housing and the inner casing l are joined together as disclosed in FIG. 3. As shown therein, the inner casing l is provided with flange 10b which engages and is secured to flange 10a of rear panel 10. The inwardly directed flanges 19 are provided with slits 24 through which the locking members 30 on the flanges 10a and lb are inserted thereby interlocking the rear panel and front panel 9 and the inner housing 1. 1

In FIGS. 8 and 9 it is disclosed how radiator similar to FIGS. 1 and 2, but having a slightly modified construction; might be wall-mounted. In the latter a wall or other surface shown at 40' is provided with spaced channel bars 41 carrying supporting pins 42. Brackets 44 are provided with hook portions 43 that fit around the pins 42.

The panels of the inner casing and the housing may be formed of any suitable heat-resistant material, preferably sheet metal, but other materials such as certain kinds of synthetic resin, castings etc. may be used. The plates or panels may be decorated with patterns or painted or colored to provide a desired aesthetic effect.

An important feature of the present invention is the provision of means to increase the air circulation at the heating unit in order to obtain increased heat by convection. A reasonably forceful circulation of air is desired because it makes it possible to obtain maintanence of the outer temperature conditions such as burning, which has not been possible with conventional heating units. In conventional units, the heating rods, in order to be properly cooled, must be exposed to direct contact with the room air, so that dust which is present in the air, will be exposed to combustion and this produces an undesirable odor and if the temperature is raised to C. it may cause serious burns. By providing increased air circulation according to the present invention, an effective heat removal is obtained so that the heating rods may be entirely enclosed and thus not be exposed to contact with dust-containing air. Furthermore, the temperature on the plates or panels which define the air passages may be maintained at a suitable degree such as of the order of 35C 40C and therefore will not require any special protective equipment.

While only a single one of the plates or panels 9 preferably disposed over the front face of the radiator, may be used, plates or panels may be used over both the front and back of the radiator, the back plate being that indicated at 10 in the drawings. In such case, the apertures shown at 20 and 21 might be considered as somewhat constricted in relation to the air passage.

In FIGS. 5 and 6 is shown how a radiator of the type shown in FIG. 1 might be supplied completely ready for installation on a wall 50 and with the plates, baffles or panels factory-installed. A control unit 51 associated with the radiator is shown in FIG. 5.

What is claimed is:

1. An electric heating unit comprising, a casing containing heating elements, a housing for the casing, the housing including front and back panels disposed respectively over and spaced from the front and rear surfaces of the casing, said panels defining air channels between them and the surface of the casing, the panels being spaced apart at their top and bottom, the upper and lower ends of the casing being spaced from the adjacent ends of the panels, the spacing between the panels at their upper and lower ends being constricted to provide air inlet and outlet openings of approximately the width of the air channels, the front panel having vertical edges provided with rearwardly bent rim portions, the rim portions being provided at their rear edges with inwardly directed flanges, said flanges having slits, the vertical edges of the rear panel and the heater casing being provided with a forwardly bent rim, the rims on the rear panel and casing being in juxtaposed contact with each other, the juxtaposed rims being provided with forwardly projecting hookshaped securing members and the securing members being received in slits in the flanges of the front plate to lock the front plate, rear plate and the casing together.

2. An electric heating unit according to claim 1, wherein the front panel is provided at its top with a ho]- low, triangular box that aids in the constriction of the air outlet opening, said box having a lower angular deflecting surface.

3. An electric heating unit comprising, a closed casing containing and enclosing heating elements, said casing being closed at the top and bottom and including overlapped flanges at said top and bottom, the heating elements being spaced from inner wall surfaces of the casing whereby air spacing is provided between the heating elements and the inner wall surfaces of the easing, a housing fitted around the casing and spaced therefrom to provide air spaces between the exterior surfaces of the casing and the inner wall surfaces of the housing, said housing including front and rear panels provided with juxtaposed side members disposed over and spaced from parts of the casing to thereby provide air spacing between said panels and parts of the casing, the panels being arranged to provide air inlet and outlet openings between them, the inlet opening being than that of the heating elements. 

1. An electric heating unit comprising, a casing containing heating elements, a housing for the casing, the housing including front and back panels disposed respectively over and spaced from the front and rear surfaces of the casing, said panels defining air channels between them and the surface of the casing, the panels being spaced apart at their top and bottom, the upper and lower ends of the casing being spaced from the adjacent ends of the panels, the spacing between the panels at their upper and lower ends being constricted to provide air inlet and outlet openings of approximately the width of the air channels, the front panel having vertical edges provided with rearwardly bent rim portions, the rim portions being provided at their rear edges with inwardly directed flanges, said flanges having slits, the vertical edges of the rear panel and the heater casing being provided with a forwardly bent rim, the rims on the rear panel and casing being in juxtaposed contact with each other, the juxtaposed rims being provided with forwardly projecting hookshaped securing members and the securing members being received in slits in the flanges of the front plate to lock the front plate, rear plate and the casing together.
 2. An electric heating unit according to claim 1, wherein the front panel is provided at its top with a hollow, triangular box that aids in the constriction of the air outlet opening, said box having a lower angular deflecting surface.
 3. An electric heating unit comprising, a closed casing containing and enclosing heating elements, said casing being closed at the top and bottom and including overlapped flanges at said top and bottom, the heating elements being spaced from inner wall surfaces of the casing whereby air spacing is provided between the heating elements and the inner wall surfaces of the casing, a housing fitted around the casing and spaced therefrom to provide air spaces between the exterior surfaces of the casing and the inner wall surfaces of the housing, said housing including front and rear panels provided with juxtaposed side members disposed over and spaced from parts of the casing to thereby provide air spacing between said panels and parts of the casing, the panels being arranged to provide air inlet and outlet openings between them, the inlet opening being located at the bottom of the housing below the casing and the air outlet being located at the top of the housing above the casing, at least one of the panels having hook-shaped locking members at its ends of its side members which enter slits at the ends of the side members of its companion panel to thereby hold the panels together, the spacing of the housing from the casing causing parts of the housing to be heated by convection from the heating elements and at a lower temperature than that of the heating elements. 